The man who can map the chemicals all over your body

POST DATE: 11:30 pm

Pieter Dorrestein uses mass spectrometry to eavesdrop on the molecular conversations between microbes and their world.

Apart from the treadmill desk, Pieter Dorrestein’s office at the University of California, San Diego (UCSD), is unremarkable: there is a circular table with chairs around it, bookshelves lined with journals, papers and books, and a couple of plaques honouring him and his work.

But Dorrestein likes to offer visitors a closer look. On his computer screen, he pulls up a 3D rendering of the space. Four figures seated around the table — one of whom is Dorrestein — look as if they’ve been splashed with brightly coloured paint. To produce the image, researchers swabbed every surface in the room, including the people, several hundred times, then analysed the swabs with mass spectrometry to identify the chemicals present.